This invention relates to the accelerated aging and impregnation of electrolytic capacitors having formed anodes while centrifuging under reduced pressure first at less than desired voltage until impregnation is complete and then at final desired voltage.
Capacitors are aged by applying voltage to repair any damage to anodized electrode foils occurring during the assembly of the capacitor or to repair weak places or imperfections in the anodized layer. It is recognized that the same minimum leakage current can be obtained immediately after the aging process with both perfectly and imperfectly aged capacitors, and it is believed that entrapped bubbles of hydrogen, produced during the aging process are responsible for this anomaly.
Various methods have been devised to reduce this anomaly including aging for longer times and/or at higher temperatures, and aging while impregnating the capacitor. It has also been taught to apply vibration while impregnating and aging the capacitor and/or reduce the pressure. It has been suggested that a centrifugal impregnation process while forming the capacitor be applied to the aging process.